Composting of crucifer wastes using geotextile covers

Composting trials were undertaken in 1994 - 996 in Ste. Anne de Bellevue, Q uebec, to study the feasibility of using crucifer or carrot residues with s awdust or straw for composting. Geotextile covers were tested for their inf luence on different parameters of the composting process. Two complete comp osting cycles from fall to summer were monitored. Measurements were taken f or compost temperature, moisture, and leachate. Chemical analyses were perf ormed on compost samples. Phytotoxicity tests were done with compost leacha te samples. The results indicated that temperatures of covered compost (CC) decreased more slowly during late fall and early winter than non-covered c ompost (NC). In addition, CC did not freeze to as great a depth during the winter, and warmed earlier and faster than NC in the spring. The moisture c ontent of CC was significantly lower than in NC at the end of both composti ng cycles. CC had a higher mineral content than NC in both cycles, and the levels of total N, r, K and NO3 were significantly higher for CC in the sec ond cycle. The carbon/nitrogen (C/N) ratio of CC decreased earlier and reac hed a lower level at the end of the composting cycle. The quantity of leach ate from CC was significantly reduced compared to NC in the second cycle. C ompost leachate in both treatments showed a high level of phytotoxicity at the beginning of the composting cycle. However, there was no evidence that compost covers influenced the phytotoxicity in leachate throughout the comp osting cycle. The use of covers could translate into economic or environmen tal benefits for most composting operations.